Compressed-cork article and method of making the same



Sept. 20, 1927.

H. F. BUSCH Filed April 28. 1926 ALM 511x464 Patented Sept. 20, 1927.

UNITED STATES PATENT: OFFICE. I

HERMAN F. BUSGH, OF HILLVALE, PENNSYLVANIA, ASSIGNOB' TO ARMSTRONG CORK COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

COMPRESSED-CORK ARTICLE D METHOD OF MAKING THE SAME.

Application filed April as, 192's. Serial no. 105,201.

The present invention relates to compressed artificial cork articles and more especially to pulleys having frictional surfaces of compressed artificial cork. The invention will be described with particular ing the pulley, the cork is preferably molded around the usual shaft engaging sleeve of the pulley so as to become united therewith during the moulding operation.

Compressed artificial cork is made of cork granules and a suitable binder compressed and set under heat, forming a compact homogeneous mass of cork. Any of the. usual formulae for making artificial cork may be employed, but preferably Iu'se as a basis, granulated cork and glycerine formaldehydemix described in Busch Patent 1,532,682of- April 7, 1925 and 1,269,682 of June 18-, 1918. The size of thecork granules is not particularly important, and granules of any of the usual sizes for making compressed artificial cork may be used.

The mixture of cork-granules and binder is compressed to form a har'dmass of high structural strength and wear resisting qualities. The mass should be compressed to a volume notover about 1/12 that of the volume of. the uncompressed mix and preferably not 'over' 1/16 ojtheoriginal volume. The most satisfactory results have been obtained witha compression of 20 to 1. The mass is set under heat which sets the binder and holds thecork in its highly compressed con dition. Thefbinder' also servesito firmly ce- 'ment"the corkmass to the pulley sleeve or mandrel, the mouldinwith the action of the binder forminga very firm union. between the metal and the cork.

In the accompanying drawings, which il---' lustrate the .preierred embodiment of the invention;-

- Figure 1 is a longitudinal sectional view ing is maintained in'the part of of the cork around the sleeve under lug pressure combined Figure 2 is of Figure 1;

Figure 3 is a view similar to Figure 2, but

showing a 'modified structure; and,

Figure 4 is a vertical sectional view showing the present ing the pulley.

Referring to the illustrated embodiment, the pulley 2 (Figure 1) has a highly compreferred method of mould- .pressed artificial cork body 3 which sur-' rounds and is carried by a suitable .metal a section on the line IIII sleeve or mandrel, and upon which is formed a working face 5. The working face 5is illustrated as being crowned to engage a belt, but obviouslythe face maybe adapted to engage power transmission means other than belts.

The binder used for the work cements it firmly to the sleeve4. A non-rotative engagementbetween the cork 3 and thesleeve 4.- is'furtherinsured by the fins 6.

A modification of this arrangement is illustrated in Figure 3, wherein a sleeve 4: is

.provided with slots '10 into which the cork comprising the pulley body 3 is pressed thereby forming .a tight connection between I preferably form the pulley in a cylindrical mold 11 (Figure 4) in which the f sleeve 4' is concentrically supported on a plug .12. The plug 12 ismaintained in position by a disk 13 surrounding the plug and engaging the mold 11. The plug 12 also serves 7 as a core,-forming an. opening, substantiallyequal to the diameter of the sleeve 4, in the.

lend-of the body 3- whichprojects beyond the sleevel. In a similar manner an openthe body a which projects beyond the sleeve 4 by 9. cylindrical core 14: which abuts'the end of the sleeve 4 and efiectively prevents any cork material'being pressed into the interior of 4 the sleeve 4.; r

In forming the pulley, cork' material 15 is compressedin the mold 11 around the sleeve 4 and core 14 and plu 12 by means of rings .16 and 17 which shdably fit @tvithin the cavity of the mold 1 1. The ring 16, closely fitting around the plu 12, is maintained against-the pressure app to the cork ma-- terial by means of pins 18 which project through holes in the wall of the mold 11 and engage the rin 16. Pressure is applied to the cork material 15 by the ring 17 which is forced into the mold by a hollow cylindrical plunger 19 loosely enclosin the core 14. In

igure 4, the ring 17 an plunger 19 are shown in position at the end of the stroke with pins 20, similar to pins 18, inserted through holes in the wall of the mold 11 en ga in the rin 17 and reventin expansion of the cork ma terial 15. With tlge cork material 15 confined as shown in Figure 4, the pulley is heated an amount sufiicient to set the binder, which holds the cork in its highly compressed condition and also cements it to the sleeve 4. After the mass is cooled, the pulley is taken from the mold and the worklng face 5 is shaped in accordance with the work it is to perform. The compression ratio, as above indicated, is preferably in the nei hborhood of 20 to 1. Such compression yiel s an artificial cork having a hard wear-resisting surface. Such compression results in the density of the material being considerably increased, and results in a strong hard body. The density and strength of the compressed material are considerably greater than those obtainable in ordinary artificial cork, the density of the material compressed in this ratio'being about pounds per cubic foot, while ordinary artificial cork has a density of about 30 pounds per cubic foot; 4

The compression substantially along the axis of the pulley results in the cork granules being compressed into thin fiat disks, the planes of compression of which are normal to the axis of the pully. Flattened granules are therefore disposed edgewise to the work ing face of the pulley and since each granule is rooted in the body of the cork, the working face has greater wear resisting qualities and there is no tendency for the granules to put]? up or scale oil as might be the case if the granules lay flat upon the working surface.

A textile roll havin this arrangement of the cork anules to t e working surface is disclosed 1n the Busch Patent 1,532,682 but the material in such patent is different from.

that herein described in that it iscompressed to but about 1/8 of its initial volume sothat the cork is highly resilient and presents a yielding surface, desired for textile rolls, whereas the material herein described is preferably compressed to form a hard substantial unyielding mass, which, while havin .the high. frictional qualities characteristlc of cork, possesses the, structural strength and wearing qualities necessary for power transmitting pulleys.

From the drawings it will be seen that the sleeve 4 does not extend completely through the alley 2. It is not necessa that it she d do so, since the body 3 has 11 compressed to such an extent that it is a'strong and relatively hard mass capable of bearing considerable load and torsional stress. F urthermore, the portions of the pulley which extend beyond the sleeve 4 are effective for grip ing the ends of the fins G and takin any ongitudinal thrust which may be placed on the pulley. This latter feature is not required in an ordinary belt pulley, however, because the great pressure to which the cork material in the mold is subjected causes the body 3 to firmly grip the sleeve 4, enclosing any projectionsthereon or entering any slots or indentations therein, thereby forming a pulley easily capable of withstanding an torsional or longitudinal stresses to which it may be subjected.

Thus I providea pulley having a hard, substantially unyielding, wear-resisting working face possessed of inherently good frictional qualities. The mass of artificial cork comprising the body portion is hard and strong, firmly gripping the metal sleeve on which the alloy is mounted.

It is un erstood that the reduction ratio of twenty to one is desirable, but this ratio is not to be construed as a limiting ratio. There is, of course, a limit of compressibility for the artificial cork, which may not be exceeded. On the other hand, a small degree of compression results in a pulley face, similar to ordinary artificial cork, lacking the strength and wearre'sisting qualities found in my improved pulley.

While I have specifically illustrated and described the preferred embodiment of my invention, it is to be understood that the invention is not limited to the details above set forth, but that the invention may be otherwise embodied within the scope of the following claims.

I claim:

1. A pulley having a working surface of artificial cork compressed to a volume not over about 1/12 that of the uncompressed artificial cork mix.

2. A pulley having a working face of artificial cork compressed to about 1/20 of the initial volume of the uncompressed artificial cork mix. y

3. A pulleyhaving a working face of artificial cork compressed to a volume not over 1/12th that of the uncompressed artificial 1/20 of the normal volume of the initial uncompressed artificial cork mix in such a direction as to cause the granules to be disposed edgewise to the working surface of the pulley.

8. The method of making a pulley comprising a sleeve and a surrounding body of compressed artificial cork which includes positioning the sleeve in a mold, placing the artificial cork mix around and in contact with the sleeve, and compressing the artificial cork in a direction substantially parallel to the axis of the sleeve to materially less than 1/12 of the normal volume of the uncompressed cork mix.

9. The method of making a pulley comprising a sleeve and a surroundlng body of artificial cork to about pounds per cubic foot, and subjecting the compressed mass to heat to set the binder and cement the cork mass to the sleeve.

10. As a new article of manufacture a body of artificial cork compressed to a volume not over about 1/12 that of the initial volume of the uncompressed artificial cork mix.

11. As a new article of manufacture a body of compressed artificial cork including a binder and cork granules compressed to a density substantially greater than 30 pounds per cubic foot.

12. As a new article of manufacturea body of com ressed artificial cork including a binder an cork granules compressed to a gensity of substantially 60 pounds per cubic oot.

' 13. As a new article of manufacture a body of compressed artificial cork including a binder and cork ranules compressed to about 1/20 of the initial volume of the uncompressed artificial cork mix.

14. The method of making a pulley comprising a sleeve and a surrounding body of artificial cork having a binder, which includes positioning the sleeve in a mold, placing the artificial cork mix around and in contact with the sleeve, compressing the artificial cork in a direction substantially axial of the sleeve to substantially less than 1/12th of the normal volume of the uncompressed cork mix, and subjecting the compressed mix to heat while under pressure to set the binder and cement the cork body to the sleeve.

In testimony whereof I have hereunto set 111 hand.

y HERMAN F. BUSCH. 

